For a variety of reasons, heart valves, such as the mitral valve, can become enlarged. As the mitral valve, for instance, enlarges, the function of the heart can be detrimentally affected. If the valve becomes sufficiently enlarged, cooperating surfaces fail to meet and the valve ceases to function properly leading to severe heart problems or potentially heart failure.
A relatively common surgical procedure designed to correct the enlarged valve involves implantation of an annuloplasty ring. During this procedure, an annuloplasty ring is sewed to the tissue surrounding the subject heart valve. The annuloplasty ring effectively braces or holds the valve at an appropriate size to permit proper functioning of the heart valve.
In the typical procedure, the annuloplasty ring is attached to the tissue surrounding the mitral valve. The size of the anterior leaflet for a given heart valve dictates the size of the annuloplasty ring to be implanted. Accordingly, the anterior leaflet must be measured to permit proper sizing of the annuloplasty ring for a given heart and patient.
Conventionally, the anterior leaflet of the mitral valve is stretched as if it were closed and sized with an annuloplasty ring sizer. The surgeon typically has available several ring sizers having ends of predetermined sizes. Once the given anterior leaflet is matched with a corresponding annuloplasty ring sizer, the surgeon is able to select an appropriate annuloplasty ring.
The anterior leaflet of the mitral valve is stretched for sizing by inserting a pair of nerve hooks into the proximate chordae tendinae and pulling the chordae tendinae in different directions via the pair of nerve hooks. The chordae tendinae are attached to the anterior and posterior papillary muscles surrounding the anterior leaflet and effectively prevent the anterior leaflet area from prolapsing into the left atrium during normal valve function. The anterior leaflet is position for sizing when the chordae tendinae are pulled by the nerve hooks.
Because each nerve hook requires one hand to pull the chordae tendinae in a specific direction, the sizing operation requires the use of three hands. As a result, the surgeon performing the procedure requires assistance from another person in a relatively small physical area during a delicate procedure. It would be advantageous to have an instrument that would allow a surgeon to properly pull the chordae tendinae with a single hand, thus leaving his or her other hand free for insertion of the annuloplasty ring sizer.